Children with a history of absence seizure must be supervised carefully while swimming or bathing, because of the danger of drowning.

They may also be restricted from driving and other potentially hazardous activities.

• Absence seizures are generally believed to be more common in females and in males
• Absence epilepsy with myoclonus has a male predominance
• Childhood absence epilepsy onset is at age 4-8 years, with peak onset at age 6-7 years
• Juvenile absence epilepsy onset is generally around puberty

Signs and Symptoms

• Staring, without unusual movement
• Lip smacking
• Fluttering eyelids
• Chewing
• Hand movements
• Absence seizures last only a few seconds

Full recovery is almost instantaneous. Afterward, there is no confusion, but also no memory of the incident.

Some people experience hundreds of these episodes each day, which interferes with their performance at school or work.

Decline in school performance may be an indication of the onset or breakthrough of absence seizures.

• Physical examination may reveal stigmata of a genetic disease, such as a neurocutaneous disorder (eg, tuberous sclerosis) or an inborn error of metabolism

• Neurologic examination may show signs of developmental delay or more specific signs, such as spastic paresis in cerebral palsy

Cause

In most cases, no underlying cause can be found for absence seizures.

• Some children simply seem to have a genetic predisposition to them

• Sometimes flashing lights or hyperventilation, nervous, stressful, uncomfortable situations, or other strong sensory stimuli may trigger seizures
• Drugs that lower the seizure threshold (eg, alcohol, cocaine, high-dose penicillin, isoniazid [INH] overdose, neuroleptics) are most likely to cause seizures in patients with epilepsy

Tests and diagnosis

Some children experience episodes that resemble absence seizures, but aren't truly seizures. This most often occurs in children with mental retardation, autism or attention-deficit/hyperactivity disorder.

Blood count

• EEG- A bilateral synchronous, symmetrical 3-Hz spike-and-wave discharge EEG pattern accompanies absence seizures
• Brain scans- CT or MRI

Complications

While most children outgrow absence seizures, some people continue to have these types of seizures throughout their lives.

• In some cases, people who have petit mal seizures eventually begin experiencing full convulsions (grand mal or generalized tonic-clonic seizures)
• Learning disabilities
• Absence status epilepticus, a condition in which seizure behavior lasts longer than a few minutes

Treatment

The most effective medications for petit mal seizures include

• Ethosuximide
• Valproic acid
• Lamotrigine

Most children can discontinue anti-seizure medications, under a doctor's supervision, after they've been seizure-free for two years.

Each of these medications has potential side effects, some of them possibly serious, which makes it important that the patient and/or their caregivers understand the specific medication prescribed.

Diet

Patients with medically intractable seizures may be tried on a ketogenic or medium-chain triglyceride diet

Activity

• Physical activity should not be restricted any more than necessary
• Activities, in which a seizure might pose a threat, such as swimming or rock climbing, may be allowed with appropriate supervision
• A child with epilepsy should not be unnecessarily handicapped. Patients with uncontrolled absence seizures should not be allowed to drive
• The situation may be unclear when the patient's clinical seizures are controlled but the EEG still shows some spike-wave activity.